The invention relates to heat exchangers, especially radiators for motor vehicles, with pipes or tubes opening into upper and lower water boxes for the guidance of heat exchange fluid, which pipes are arranged parallel to one another, and with heat exchanger fins extending perpendicularly to the pipes and fixedly connected thereto. The fins on at least one of the surfaces exhibit cut-outs which are expanded toward the inside to form a groove and serve for the attachment of lateral parts, which lateral parts grip with tabs into the groove formed by the cut-outs.
Heat exchangers wherein the lateral parts are not connected at the water boxes, but rather at the heat exchange fins themselves, are known, for example, from German published application DE-OS 24 18 132. The lateral parts are there formed respectively in one part and connected at the fins by stamped-out tabs which are bent more than 90.degree. out of the plane of the lateral part by a bending work tool so that the tabs abut against angularly extending inner walls of a groove formed at the fins. Because with this kind of attachment of the lateral parts a bending work tool is necessary, the opening width of the cut-outs in the fins and the correspondingly formed groove must be large enough to accommodate the insertion and utilization of the bending tool. See also U.S. Pat. No. 3,795,274 showing arrangements for clamping the radiator fins utilizing grooves formed at the lateral outside surfaces of the fins. These requirements, especially with heat exchangers having a small construction depth, can not always be fulfilled, so that an attachment in this manner is then not possible. The invention is based upon the problem to create a heat exchanger wherein the lateral parts can be simply attached directly at the fins, even in radiator fin blocks having a small construction depth or thickness.
This problem is solved according to the invention by providing that each lateral part is formed of two halves which are provided respectively with side edges which are pivotally connected with one another along an axis extending in the direction of the groove in the fins and which halves are both provided with tabs which extend outwardly from the respective side edges into the groove to abut against the lateral groove walls. In order to create a rigid and stiff connection between the lateral halves after their installation in the groove, closing elements are provided.
With the arrangement of the invention it is possible to connect the two halves of the lateral parts together without a bending work tool. Because the lateral halves are pivotable about an axis extending in the direction of the groove they can be first so disposed with respect to one another that they form a sharp angle with respect to one another with the tabs of both lateral parts extending in somewhat the same direction and in almost the same plane. They then exhibit only a small spacing from one another (as seen in the direction along the pivot axis) so that they can easily be installed into a small opening of the inwardly expanding groove at the fins. Thereafter, the lateral halves are pivoted with respect to one another so that the angle between them and also between the tabs is enlarged. In this way, the tabs of the halves abut respectively onto the oppositely disposed inwardly diverging walls of the groove formed in the fins. Therefore, no bending work tool is necessary to install the lateral halves so that the cut-outs in the fins forming the connecting groove can be formed relatively small. Especially with heat exchanger or radiator blocks having a narrow or small construction thickness, this is an advantage. It is also advantageous that the lateral parts can be installed at the heat exchanger at a later stage of manufacture. After the insertion of the tabs and the pivoting of the lateral part halves with respect to one another, the lateral part halves are rigidly connected to one another by closing elements so that the strength connection at the fin block is fixed and cannot come loose by itself.
It is advantageous if the tabs are set-off with respect to one another like the teeth of a comb to form a certain separation or division with respect to one another, with the tabs of the respective other identically formed but sideways disposed lateral part half being interlacingly gripped with their respective tabs. Because of the identical formation of the lateral part halves, it is possible to manufacture the same of indefinite length according to especially preferred embodiments. It is then unnecessary to be concerned with the sidewise disposition of the two halves during their formation. Furthermore, the manufacture of such lateral part halves is then very simple.
According to a further construction feature of the invention, the cut-outs are widened in a dove-tailed shape and the tabs are formed as straight tabs which are disposed at an angle with respect to the associated lateral part half, which angle is greater than 90.degree.. This configuration of the tabs is especially simple to manufacture and assemble.
It is also advantageous according to preferred embodiments of the invention to provide that the tabs are formed with a hook-shape and are provided with respective slots which are disposed immediately adjacent the lateral edges of the halves and extend in the axial direction and exhibit a width which is at least the thickness of the lateral part halves. The lateral part halves are then connected with one another before they are installed into the groove and are installed as a single unit. The actual pivot axes of the lateral part halves with respect to one another are thereby formed by and at said slots. To secure against the sliding of the fastened lateral part halves in the direction of the groove (axial direction of the groove formed by the cut-outs in the fins) it is furthermore advantageous if the tabs are provided with teeth which engage into the heat exchanger fins.
For lateral part halves which are made of sheet metal, it is advantageous according to a feature of the invention to fix a sheet metal plate to the lateral part halves as the closing or locking element. This sheet metal plate preferably extends laterally over both lateral halves and is welded together with the halves at their upper sides.
According to other preferred embodiments, the lateral parts are manufactured out of injection molded plastic parts whereby they can be formed together as a single part if they are connected to one another with a film hinge along the pivot axis. It is then also contemplated to use a holder as a closing element, which holder sits with a floor plate on the lateral parts and exhibits openings in the floor plate that accommodate a hooking or latching connection by means of nubs extending into the holes. In this manner, on the one hand, the lateral part halves are reliably fastened to the holder and on the other hand, they are simultaneously serving for the closing connection of the lateral part halves. It is also contemplated to provide embodiments wherein, instead of a special separate holder, a holder is formed together as a single part with the lateral part halves from the walls thereof so that no additional holder is necessary.
According to a further advantageous feature of certain preferred embodiments of the inVention, it is provided that the lateral part halves are provided with wall sections bent 90.degree. from the front surface of the heat exchanger fins and abutting sideways on the lateral outer edges of the heat exchanger fins so that the lateral parts effectively grip the heat exchanger fins between these wall sections. In these arrangements, the position of the lateral parts at side surfaces of the fins is fixed very reliably and a possible shoving of the lateral part halves in the direction of the groove is avoided. It is then also possible to use as a closing element, a pin, stuck through holes through the wall cut-outs, and which pins extend beyond the wall cut-outs, and are there bent upward on their ends.
Further objects, features, and advantages of the present invention will become more obvious from the following description when taken in connection with the accompanying drawings which show, for purposes of illustration only, several embodiments in accordance with the present invention.